Any idea what caused this?

[Doug E]

Here's what I saw when looking through the sump plate opening up inside the case:




Any ideas what might have caused these markings? Crazy thing is they are visible in a bunch of other areas as well. Nothing in the paperwork from the 3 previous owners indicates there was ever a catestrophic engine problem.

Car is an '81 SC with 97k miles.

TIA.

[Doug Zielke]

Sorry, Doug, I'm old and not very good at puzzles.
What are we supposed to be looking at here?

[Doug E]

Evening Doug - this view is looking up from the bottom of the case through the sump plate opening. The brown tube in the bottom of the picture is part of the oil pump and the goldish areas are part of the case casting. In the center of the picture (just above the brown tube) you can see one of the connecting rods.

When I rub my fingers across the surface you can feel the slight indentations so I can only assume something was bouncing around down there at one point.

If in fact something was down there I'm guessing it would have to had come from either the oil pump itself or through the return tubes.

I guess it's possible it come from the factory that way but it seems unlikely.

Any ideas?

[Wayne 962]

Looks like something ws bouncing around in there at one time. Previous failure?

-Wayne

[Doug Zielke]

Originally posted by Doug E

Any ideas?

None at all.

At least you'd hope the motor did not have some sort of (big) failure in a past ownership.

Are you going to split the cases to have a better look?

[Doug E]

No, I wasn't planning on splitting the case. I spent a lot of time looking around with a mirror up in there and the markings don't appear to be anywhere else.

I'm going to go back through the records to see if I can piece anything together.

[dad911]

Did the oil look ok?

[Doug E]

Yes, oil has looked OK over the past 5 oil changes I've done. There has also never been any shavings/particles on the magnetic drain cap.

I can only assume it happened sometime in the distant past ...

[69 911s]

Looks like some hamfist used a scraper harder than the case during a previous case cleaning. that would also explain why the markings appear elsewhere...

[oneblueyedog]

I went out into my garage to look at my case halves. Are you talking about the grinder marks on the webbings? It looks like that to me. I assume the factory ground down flash from the casting. My case halves have the same phenomenon in exactly the same places. I didn't find any stray metal in my teardown.

[Doug E]

Yes, oneblue, that is the area / marking I'm referring to. Thanks for checking against yours ... makes me feel better knowing I'm not the only one.

[Larry Harris]

Doug,
The tooling marks appear uniform in their direction. There does not appear to be any random marking as you would probably find if something had come loose in the lower end. I'll agree with oneblue as to the probability these marks were made either at the factory or some overly enthusiastic rebuilder.

Larry Harris

[jgparker]

I was doing an oil change this morning, and noticed the same marks inside my 2.8. It sure looks like random nicks from a high speed grinder to me. I'd assume it was from a manufacturing process or rebuild work, rather than a catastrophic event.

[Peterfrans]

I received my case back from the machinist yesterday and also have markings from grinding in the same areas.